astobj2_container.c

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/* astobj2 - replacement containers for asterisk data structures.
 *
 * Copyright (C) 2006 Marta Carbone, Luigi Rizzo - Univ. di Pisa, Italy
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*! \file
 *
 * \brief Functions implementing astobj2 objects.
 *
 * \author Richard Mudgett <[email protected]>
 */

#include "asterisk.h"

#include "asterisk/_private.h"
#include "asterisk/astobj2.h"
#include "astobj2_private.h"
#include "astobj2_container_private.h"
#include "asterisk/cli.h"

/*!
 * return the number of elements in the container
 */
int ao2_container_count(struct ao2_container *c)
{
   return ast_atomic_fetchadd_int(&c->elements, 0);
}

int __container_unlink_node_debug(struct ao2_container_node *node, uint32_t flags,
   const char *tag, const char *file, int line, const char *func)
{
   struct ao2_container *container = node->my_container;

   if (container == NULL && (flags & AO2_UNLINK_NODE_DEC_COUNT)) {
      return 0;
   }

   if ((flags & AO2_UNLINK_NODE_UNLINK_OBJECT)
      && !(flags & AO2_UNLINK_NODE_NOUNREF_OBJECT)) {
      __ao2_ref(node->obj, -1, tag ?: "Remove obj from container", file, line, func);
   }

   node->obj = NULL;

   if (flags & AO2_UNLINK_NODE_DEC_COUNT) {
      ast_atomic_fetchadd_int(&container->elements, -1);
#if defined(AO2_DEBUG)
      {
         int empty = container->nodes - container->elements;

         if (container->max_empty_nodes < empty) {
            container->max_empty_nodes = empty;
         }
         if (container->v_table->unlink_stat) {
            container->v_table->unlink_stat(container, node);
         }
      }
#endif   /* defined(AO2_DEBUG) */
   }

   if (flags & AO2_UNLINK_NODE_UNREF_NODE) {
      /* Remove node from container */
      ao2_ref(node, -1);
   }

   return 1;
}

/*!
 * \internal
 * \brief Link an object into this container.  (internal)
 *
 * \param self Container to operate upon.
 * \param obj_new Object to insert into the container.
 * \param flags search_flags to control linking the object.  (OBJ_NOLOCK)
 * \param tag used for debugging.
 * \param file Debug file name invoked from
 * \param line Debug line invoked from
 * \param func Debug function name invoked from
 *
 * \retval 0 on errors.
 * \retval 1 on success.
 */
int __ao2_link(struct ao2_container *self, void *obj_new, int flags,
   const char *tag, const char *file, int line, const char *func)
{
   int res;
   enum ao2_lock_req orig_lock;
   struct ao2_container_node *node;

   if (!__is_ao2_object(obj_new, file, line, func)
      || !__is_ao2_object(self, file, line, func)) {
      return 0;
   }

   if (!self->v_table || !self->v_table->new_node || !self->v_table->insert) {
      /* Sanity checks. */
      __ast_assert_failed(0, "invalid container v_table", file, line, func);
      return 0;
   }

   if (flags & OBJ_NOLOCK) {
      orig_lock = __adjust_lock(self, AO2_LOCK_REQ_WRLOCK, 1);
   } else {
      ao2_wrlock(self);
      orig_lock = AO2_LOCK_REQ_MUTEX;
   }

   res = 0;
   node = self->v_table->new_node(self, obj_new, tag, file, line, func);
   if (node) {
#if defined(AO2_DEBUG)
      if (ao2_container_check(self, OBJ_NOLOCK)) {
         ast_log(LOG_ERROR, "Container integrity failed before insert.\n");
      }
#endif   /* defined(AO2_DEBUG) */

      /* Insert the new node. */
      switch (self->v_table->insert(self, node)) {
      case AO2_CONTAINER_INSERT_NODE_INSERTED:
         node->is_linked = 1;
         ast_atomic_fetchadd_int(&self->elements, 1);
#if defined(AO2_DEBUG)
         AO2_DEVMODE_STAT(++self->nodes);
         if (self->v_table->link_stat) {
            self->v_table->link_stat(self, node);
         }
#endif   /* defined(AO2_DEBUG) */
         /* Fall through */
      case AO2_CONTAINER_INSERT_NODE_OBJ_REPLACED:
#if defined(AO2_DEBUG)
         if (ao2_container_check(self, OBJ_NOLOCK)) {
            ast_log(LOG_ERROR, "Container integrity failed after insert or replace.\n");
         }
#endif   /* defined(AO2_DEBUG) */
         res = 1;
         break;
      case AO2_CONTAINER_INSERT_NODE_REJECTED:
         ao2_ref(node, -1);
         break;
      }
   }

   if (flags & OBJ_NOLOCK) {
      __adjust_lock(self, orig_lock, 0);
   } else {
      ao2_unlock(self);
   }

   return res;
}

/*!
 * \brief another convenience function is a callback that matches on address
 */
int ao2_match_by_addr(void *user_data, void *arg, int flags)
{
   return (user_data == arg) ? (CMP_MATCH | CMP_STOP) : 0;
}

/*
 * Unlink an object from the container
 * and destroy the associated * bucket_entry structure.
 */
void *__ao2_unlink(struct ao2_container *c, void *user_data, int flags,
   const char *tag, const char *file, int line, const char *func)
{
   if (!__is_ao2_object(user_data, file, line, func)) {
      /* Sanity checks. */
      return NULL;
   }

   flags &= ~OBJ_SEARCH_MASK;
   flags |= (OBJ_UNLINK | OBJ_SEARCH_OBJECT | OBJ_NODATA);
   __ao2_callback(c, flags, ao2_match_by_addr, user_data, tag, file, line, func);

   return NULL;
}

/*!
 * \brief special callback that matches all
 */
static int cb_true(void *user_data, void *arg, int flags)
{
   return CMP_MATCH;
}

/*!
 * \brief similar to cb_true, but is an ao2_callback_data_fn instead
 */
static int cb_true_data(void *user_data, void *arg, void *data, int flags)
{
   return CMP_MATCH;
}

/*!
 * \internal
 * \brief Traverse the container.  (internal)
 *
 * \param self Container to operate upon.
 * \param flags search_flags to control traversing the container
 * \param cb_fn Comparison callback function.
 * \param arg Comparison callback arg parameter.
 * \param data Data comparison callback data parameter.
 * \param type Type of comparison callback cb_fn.
 * \param tag used for debugging.
 * \param file Debug file name invoked from
 * \param line Debug line invoked from
 * \param func Debug function name invoked from
 *
 * \retval NULL on failure or no matching object found.
 *
 * \retval object found if OBJ_MULTIPLE is not set in the flags
 * parameter.
 *
 * \retval ao2_iterator pointer if OBJ_MULTIPLE is set in the
 * flags parameter.  The iterator must be destroyed with
 * ao2_iterator_destroy() when the caller no longer needs it.
 */
static void *internal_ao2_traverse(struct ao2_container *self, enum search_flags flags,
   void *cb_fn, void *arg, void *data, enum ao2_callback_type type,
   const char *tag, const char *file, int line, const char *func)
{
   void *ret;
   ao2_callback_fn *cb_default = NULL;
   ao2_callback_data_fn *cb_withdata = NULL;
   struct ao2_container_node *node;
   void *traversal_state;

   enum ao2_lock_req orig_lock;
   struct ao2_container *multi_container = NULL;
   struct ao2_iterator *multi_iterator = NULL;

   if (!__is_ao2_object(self, file, line, func)) {
      return NULL;
   }

   if (!self->v_table
      || !self->v_table->traverse_first || !self->v_table->traverse_next) {
      /* Sanity checks. */
      __ast_assert_failed(0, "invalid container v_table", file, line, func);
      return NULL;
   }

   /*
    * This logic is used so we can support OBJ_MULTIPLE with OBJ_NODATA
    * turned off.  This if statement checks for the special condition
    * where multiple items may need to be returned.
    */
   if ((flags & (OBJ_MULTIPLE | OBJ_NODATA)) == OBJ_MULTIPLE) {
      /* we need to return an ao2_iterator with the results,
       * as there could be more than one. the iterator will
       * hold the only reference to a container that has all the
       * matching objects linked into it, so when the iterator
       * is destroyed, the container will be automatically
       * destroyed as well.
       */
      multi_container = ao2_t_container_alloc_list(AO2_ALLOC_OPT_LOCK_NOLOCK, 0, NULL,
         NULL, "OBJ_MULTIPLE return container creation");
      if (!multi_container) {
         return NULL;
      }
      if (!(multi_iterator = ast_calloc(1, sizeof(*multi_iterator)))) {
         ao2_t_ref(multi_container, -1, "OBJ_MULTIPLE interator creation failed.");
         return NULL;
      }
   }

   if (!cb_fn) {
      /* Match everything if no callback match function provided. */
      if (type == AO2_CALLBACK_WITH_DATA) {
         cb_withdata = cb_true_data;
      } else {
         cb_default = cb_true;
      }
   } else {
      /*
       * We do this here to avoid the per object casting penalty (even
       * though that is probably optimized away anyway).
       */
      if (type == AO2_CALLBACK_WITH_DATA) {
         cb_withdata = cb_fn;
      } else {
         cb_default = cb_fn;
      }
   }

   /* avoid modifications to the content */
   if (flags & OBJ_NOLOCK) {
      if (flags & OBJ_UNLINK) {
         orig_lock = __adjust_lock(self, AO2_LOCK_REQ_WRLOCK, 1);
      } else {
         orig_lock = __adjust_lock(self, AO2_LOCK_REQ_RDLOCK, 1);
      }
   } else {
      orig_lock = AO2_LOCK_REQ_MUTEX;
      if (flags & OBJ_UNLINK) {
         ao2_wrlock(self);
      } else {
         ao2_rdlock(self);
      }
   }

   /* Create a buffer for the traversal state. */
   traversal_state = alloca(AO2_TRAVERSAL_STATE_SIZE);

   ret = NULL;
   for (node = self->v_table->traverse_first(self, flags, arg, traversal_state);
      node;
      node = self->v_table->traverse_next(self, traversal_state, node)) {
      int match;

      /* Visit the current node. */
      match = (CMP_MATCH | CMP_STOP);
      if (type == AO2_CALLBACK_WITH_DATA) {
         match &= cb_withdata(node->obj, arg, data, flags);
      } else {
         match &= cb_default(node->obj, arg, flags);
      }
      if (match == 0) {
         /* no match, no stop, continue */
         continue;
      }
      if (match == CMP_STOP) {
         /* no match but stop, we are done */
         break;
      }

      /*
       * CMP_MATCH is set here
       *
       * we found the object, performing operations according to flags
       */
      if (node->obj) {
         /* The object is still in the container. */
         if (!(flags & OBJ_NODATA)) {
            /*
             * We are returning the object, record the value.  It is
             * important to handle this case before the unlink.
             */
            if (multi_container) {
               /*
                * Link the object into the container that will hold the
                * results.
                */
               __ao2_link(multi_container, node->obj, flags, tag, file, line, func);
            } else {
               ret = node->obj;
               /* Returning a single object. */
               if (!(flags & OBJ_UNLINK)) {
                  /*
                   * Bump the ref count since we are not going to unlink and
                   * transfer the container's object ref to the returned object.
                   */
                  __ao2_ref(ret, 1, tag ?: "Traversal found object", file, line, func);
               }
            }
         }

         if (flags & OBJ_UNLINK) {
            int ulflag = AO2_UNLINK_NODE_UNREF_NODE | AO2_UNLINK_NODE_DEC_COUNT;
            if (multi_container || (flags & OBJ_NODATA)) {
               ulflag |= AO2_UNLINK_NODE_UNLINK_OBJECT;
            }
            __container_unlink_node_debug(node, ulflag, tag, file, line, func);
         }
      }

      if ((match & CMP_STOP) || !(flags & OBJ_MULTIPLE)) {
         /* We found our only (or last) match, so we are done */
         break;
      }
   }
   if (self->v_table->traverse_cleanup) {
      self->v_table->traverse_cleanup(traversal_state);
   }
   if (node) {
      /* Unref the node from self->v_table->traverse_first/traverse_next() */
      ao2_ref(node, -1);
   }

   if (flags & OBJ_NOLOCK) {
      __adjust_lock(self, orig_lock, 0);
   } else {
      ao2_unlock(self);
   }

   /* if multi_container was created, we are returning multiple objects */
   if (multi_container) {
      *multi_iterator = ao2_iterator_init(multi_container,
         AO2_ITERATOR_UNLINK | AO2_ITERATOR_MALLOCD);
      ao2_t_ref(multi_container, -1,
         "OBJ_MULTIPLE for multiple objects traversal complete.");
      return multi_iterator;
   } else {
      return ret;
   }
}

void *__ao2_callback(struct ao2_container *c, enum search_flags flags,
   ao2_callback_fn *cb_fn, void *arg, const char *tag, const char *file, int line,
   const char *func)
{
   return internal_ao2_traverse(c, flags, cb_fn, arg, NULL, AO2_CALLBACK_DEFAULT, tag, file, line, func);
}

void *__ao2_callback_data(struct ao2_container *c, enum search_flags flags,
   ao2_callback_data_fn *cb_fn, void *arg, void *data, const char *tag, const char *file,
   int line, const char *func)
{
   return internal_ao2_traverse(c, flags, cb_fn, arg, data, AO2_CALLBACK_WITH_DATA, tag, file, line, func);
}

/*!
 * the find function just invokes the default callback with some reasonable flags.
 */
void *__ao2_find(struct ao2_container *c, const void *arg, enum search_flags flags,
   const char *tag, const char *file, int line, const char *func)
{
   void *arged = (void *) arg;/* Done to avoid compiler const warning */

   if (!c) {
      /* Sanity checks. */
      ast_assert(0);
      return NULL;
   }
   return __ao2_callback(c, flags, c->cmp_fn, arged, tag, file, line, func);
}

void *__ao2_weakproxy_find(struct ao2_container *c, const void *arg, enum search_flags flags,
   const char *tag, const char *file, int line, const char *func)
{
   void *proxy;
   void *obj = NULL;
   enum ao2_lock_req orig_lock;

   ast_assert(!!c);
   ast_assert(flags & OBJ_SEARCH_MASK);
   ast_assert(!(flags & ~(OBJ_SEARCH_MASK | OBJ_NOLOCK)));

   if (flags & OBJ_NOLOCK) {
      orig_lock = __adjust_lock(c, AO2_LOCK_REQ_RDLOCK, 1);
   } else {
      orig_lock = AO2_LOCK_REQ_RDLOCK;
      ao2_rdlock(c);
   }

   while ((proxy = ao2_find(c, arg, flags | OBJ_NOLOCK))) {
      obj = __ao2_weakproxy_get_object(proxy, 0, tag ?: __PRETTY_FUNCTION__, file, line, func);

      if (obj) {
         ao2_ref(proxy, -1);
         break;
      }

      /* Upgrade to a write lock */
      __adjust_lock(c, AO2_LOCK_REQ_WRLOCK, 1);
      ao2_unlink_flags(c, proxy, OBJ_NOLOCK);
      ao2_ref(proxy, -1);
   }

   if (flags & OBJ_NOLOCK) {
      /* We'll keep any upgraded lock */
      __adjust_lock(c, orig_lock, 1);
   } else {
      ao2_unlock(c);
   }

   return obj;
}

/*!
 * initialize an iterator so we start from the first object
 */
struct ao2_iterator ao2_iterator_init(struct ao2_container *c, int flags)
{
   struct ao2_iterator a = {
      .c = c,
      .flags = flags
   };

   ao2_t_ref(c, +1, "Init iterator with container.");

   return a;
}

void ao2_iterator_restart(struct ao2_iterator *iter)
{
   if (!is_ao2_object(iter->c)) {
      /* Sanity check. */
      return;
   }

   /* Release the last container node reference if we have one. */
   if (iter->last_node) {
      enum ao2_lock_req orig_lock;

      /*
       * Do a read lock in case the container node unref does not
       * destroy the node.  If the container node is destroyed then
       * the lock will be upgraded to a write lock.
       */
      if (iter->flags & AO2_ITERATOR_DONTLOCK) {
         orig_lock = __adjust_lock(iter->c, AO2_LOCK_REQ_RDLOCK, 1);
      } else {
         orig_lock = AO2_LOCK_REQ_MUTEX;
         ao2_rdlock(iter->c);
      }

      ao2_ref(iter->last_node, -1);
      iter->last_node = NULL;

      if (iter->flags & AO2_ITERATOR_DONTLOCK) {
         __adjust_lock(iter->c, orig_lock, 0);
      } else {
         ao2_unlock(iter->c);
      }
   }

   /* The iteration is no longer complete. */
   iter->complete = 0;
}

void ao2_iterator_destroy(struct ao2_iterator *iter)
{
   /* Release any last container node reference. */
   ao2_iterator_restart(iter);

   /* Release the iterated container reference. */
   ao2_t_ref(iter->c, -1, "Unref iterator in ao2_iterator_destroy");
   iter->c = NULL;

   /* Free the malloced iterator. */
   if (iter->flags & AO2_ITERATOR_MALLOCD) {
      ast_free(iter);
   }
}

void ao2_iterator_cleanup(struct ao2_iterator *iter)
{
   if (iter) {
      ao2_iterator_destroy(iter);
   }
}

void *__ao2_iterator_next(struct ao2_iterator *iter,
   const char *tag, const char *file, int line, const char *func)
{
   enum ao2_lock_req orig_lock;
   struct ao2_container_node *node;
   void *ret;

   if (!__is_ao2_object(iter->c, file, line, func)) {
      return NULL;
   }

   if (!iter->c->v_table || !iter->c->v_table->iterator_next) {
      /* Sanity checks. */
      __ast_assert_failed(0, "invalid iterator container v_table", file, line, func);
      return NULL;
   }

   if (iter->complete) {
      /* Don't return any more objects. */
      return NULL;
   }

   if (iter->flags & AO2_ITERATOR_DONTLOCK) {
      if (iter->flags & AO2_ITERATOR_UNLINK) {
         orig_lock = __adjust_lock(iter->c, AO2_LOCK_REQ_WRLOCK, 1);
      } else {
         orig_lock = __adjust_lock(iter->c, AO2_LOCK_REQ_RDLOCK, 1);
      }
   } else {
      orig_lock = AO2_LOCK_REQ_MUTEX;
      if (iter->flags & AO2_ITERATOR_UNLINK) {
         ao2_wrlock(iter->c);
      } else {
         ao2_rdlock(iter->c);
      }
   }

   node = iter->c->v_table->iterator_next(iter->c, iter->last_node, iter->flags);
   if (node) {
      ret = node->obj;

      if (iter->flags & AO2_ITERATOR_UNLINK) {
         /* Transfer the object ref from the container to the returned object. */
         __container_unlink_node_debug(node, AO2_UNLINK_NODE_DEC_COUNT, tag, file, line, func);

         /* Transfer the container's node ref to the iterator. */
      } else {
         /* Bump ref of returned object */
         __ao2_ref(ret, +1, tag ?: "Next iterator object.", file, line, func);

         /* Bump the container's node ref for the iterator. */
         ao2_ref(node, +1);
      }
   } else {
      /* The iteration has completed. */
      iter->complete = 1;
      ret = NULL;
   }

   /* Replace the iterator's node */
   if (iter->last_node) {
      ao2_ref(iter->last_node, -1);
   }
   iter->last_node = node;

   if (iter->flags & AO2_ITERATOR_DONTLOCK) {
      __adjust_lock(iter->c, orig_lock, 0);
   } else {
      ao2_unlock(iter->c);
   }

   return ret;
}

int ao2_iterator_count(struct ao2_iterator *iter)
{
   return ao2_container_count(iter->c);
}

void container_destruct(void *_c)
{
   struct ao2_container *c = _c;

   /* Unlink any stored objects in the container. */
   c->destroying = 1;
   ao2_t_callback(c, OBJ_UNLINK | OBJ_NODATA | OBJ_MULTIPLE, NULL, NULL,
      "container_destruct called");

   /* Perform any extra container cleanup. */
   if (c->v_table && c->v_table->destroy) {
      c->v_table->destroy(c);
   }

#if defined(AO2_DEBUG)
   ast_atomic_fetchadd_int(&ao2.total_containers, -1);
#endif
}

/*!
 * \internal
 * \brief Put obj into the arg container.
 * \since 11.0
 *
 * \param obj  pointer to the (user-defined part) of an object.
 * \param arg callback argument from ao2_callback()
 * \param flags flags from ao2_callback()
 *
 * \retval 0 on success.
 * \retval CMP_STOP|CMP_MATCH on error.
 */
static int dup_obj_cb(void *obj, void *arg, int flags)
{
   struct ao2_container *dest = arg;

   return ao2_link_flags(dest, obj, OBJ_NOLOCK) ? 0 : (CMP_MATCH | CMP_STOP);
}

int ao2_container_dup(struct ao2_container *dest, struct ao2_container *src, enum search_flags flags)
{
   void *obj;
   int res = 0;

   if (!(flags & OBJ_NOLOCK)) {
      ao2_rdlock(src);
      ao2_wrlock(dest);
   }
   obj = ao2_callback(src, OBJ_NOLOCK, dup_obj_cb, dest);
   if (obj) {
      /* Failed to put this obj into the dest container. */
      ao2_t_ref(obj, -1, "Failed to put this object into the dest container.");

      /* Remove all items from the dest container. */
      ao2_callback(dest, OBJ_NOLOCK | OBJ_UNLINK | OBJ_NODATA | OBJ_MULTIPLE, NULL,
         NULL);
      res = -1;
   }
   if (!(flags & OBJ_NOLOCK)) {
      ao2_unlock(dest);
      ao2_unlock(src);
   }

   return res;
}

/*!
 * \brief Copy obj associated with a weakproxy into the arg container.
 *
 * \param proxy pointer to the weakproxy.
 * \param arg callback argument from ao2_callback()
 * \param flags flags from ao2_callback()
 *
 * \retval 0 on success.
 * \retval CMP_STOP|CMP_MATCH on error.
 */
static int dup_weakproxy_cb(void *proxy, void *arg, int flags)
{
   void *obj = ao2_weakproxy_get_object(proxy, 0);
   struct ao2_container *dest = arg;
   int ret;

   if (!obj) {
      return 0;
   }

   ret = ao2_link_flags(dest, obj, OBJ_NOLOCK) ? 0 : (CMP_MATCH | CMP_STOP);
   ao2_ref(obj, -1);

   return ret;
}

int ao2_container_dup_weakproxy_objs(struct ao2_container *dest, struct ao2_container *src, enum search_flags flags)
{
   void *obj;
   int res = 0;

   if (!(flags & OBJ_NOLOCK)) {
      ao2_rdlock(src);
      ao2_wrlock(dest);
   }
   obj = ao2_callback(src, OBJ_NOLOCK, dup_weakproxy_cb, dest);
   if (obj) {
      /* Failed to put this obj into the dest container. */
      ao2_t_ref(obj, -1, "Failed to put this object into the dest container.");

      /* Remove all items from the dest container. */
      ao2_callback(dest, OBJ_NOLOCK | OBJ_UNLINK | OBJ_NODATA | OBJ_MULTIPLE, NULL,
         NULL);
      res = -1;
   }
   if (!(flags & OBJ_NOLOCK)) {
      ao2_unlock(dest);
      ao2_unlock(src);
   }

   return res;
}

struct ao2_container *__ao2_container_clone(struct ao2_container *orig, enum search_flags flags, const char *tag, const char *file, int line, const char *func)
{
   struct ao2_container *clone;
   int failed;

   /* Create the clone container with the same properties as the original. */
   if (!__is_ao2_object(orig, file, line, func)) {
      return NULL;
   }

   if (!orig->v_table || !orig->v_table->alloc_empty_clone) {
      /* Sanity checks. */
      __ast_assert_failed(0, "invalid container v_table", file, line, func);
      return NULL;
   }

   clone = orig->v_table->alloc_empty_clone(orig, tag, file, line, func);
   if (!clone) {
      return NULL;
   }

   /* This test is correct.  clone must be locked before calling
    * ao2_container_dup when the OBJ_NOLOCK flag is set, otherwise
    * we could have errors in __adjust_lock. */
   if (flags & OBJ_NOLOCK) {
      ao2_wrlock(clone);
   }
   failed = ao2_container_dup(clone, orig, flags);
   if (flags & OBJ_NOLOCK) {
      ao2_unlock(clone);
   }
   if (failed) {
      /* Object copy into the clone container failed. */
      __ao2_ref(clone, -1, tag ?: "Clone creation failed", file, line, func);
      clone = NULL;
   }
   return clone;
}

void ao2_container_dump(struct ao2_container *self, enum search_flags flags, const char *name, void *where, ao2_prnt_fn *prnt, ao2_prnt_obj_fn *prnt_obj)
{
   if (!is_ao2_object(self) || !self->v_table) {
      prnt(where, "Invalid container\n");
      ast_assert(0);
      return;
   }

   if (!(flags & OBJ_NOLOCK)) {
      ao2_rdlock(self);
   }
   if (name) {
      prnt(where, "Container name: %s\n", name);
   }
#if defined(AO2_DEBUG)
   if (self->v_table->dump) {
      self->v_table->dump(self, where, prnt, prnt_obj);
   } else
#endif   /* defined(AO2_DEBUG) */
   {
      prnt(where, "Container dump not available.\n");
   }
   if (!(flags & OBJ_NOLOCK)) {
      ao2_unlock(self);
   }
}

void ao2_container_stats(struct ao2_container *self, enum search_flags flags, const char *name, void *where, ao2_prnt_fn *prnt)
{
   if (!is_ao2_object(self) || !self->v_table) {
      prnt(where, "Invalid container\n");
      ast_assert(0);
      return;
   }

   if (!(flags & OBJ_NOLOCK)) {
      ao2_rdlock(self);
   }
   if (name) {
      prnt(where, "Container name: %s\n", name);
   }
   prnt(where, "Number of objects: %d\n", self->elements);
#if defined(AO2_DEBUG)
   prnt(where, "Number of nodes: %d\n", self->nodes);
   prnt(where, "Number of empty nodes: %d\n", self->nodes - self->elements);
   /*
    * XXX
    * If the max_empty_nodes count gets out of single digits you
    * likely have a code path where ao2_iterator_destroy() is not
    * called.
    *
    * Empty nodes do not harm the container but they do make
    * container operations less efficient.
    */
   prnt(where, "Maximum empty nodes: %d\n", self->max_empty_nodes);
   if (self->v_table->stats) {
      self->v_table->stats(self, where, prnt);
   }
#endif   /* defined(AO2_DEBUG) */
   if (!(flags & OBJ_NOLOCK)) {
      ao2_unlock(self);
   }
}

int ao2_container_check(struct ao2_container *self, enum search_flags flags)
{
   int res = 0;

   if (!is_ao2_object(self) || !self->v_table) {
      /* Sanity checks. */
      ast_assert(0);
      return -1;
   }
#if defined(AO2_DEBUG)
   if (!self->v_table->integrity) {
      /* No ingetrigy check available.  Assume container is ok. */
      return 0;
   }

   if (!(flags & OBJ_NOLOCK)) {
      ao2_rdlock(self);
   }
   res = self->v_table->integrity(self);
   if (!(flags & OBJ_NOLOCK)) {
      ao2_unlock(self);
   }
#endif   /* defined(AO2_DEBUG) */
   return res;
}

#if defined(AO2_DEBUG)
static struct ao2_container *reg_containers;

struct ao2_reg_container {
   /*! Registered container pointer. */
   struct ao2_container *registered;
   /*! Callback function to print the given object's key. (NULL if not available) */
   ao2_prnt_obj_fn *prnt_obj;
   /*! Name container registered under. */
   char name[1];
};

struct ao2_reg_partial_key {
   /*! Length of partial key match. */
   int len;
   /*! Registration partial key name. */
   const char *name;
};

struct ao2_reg_match {
   /*! The nth match to find. */
   int find_nth;
   /*! Count of the matches already found. */
   int count;
};
#endif   /* defined(AO2_DEBUG) */

#if defined(AO2_DEBUG)
static int ao2_reg_sort_cb(const void *obj_left, const void *obj_right, int flags)
{
   const struct ao2_reg_container *reg_left = obj_left;
   int cmp;

   switch (flags & OBJ_SEARCH_MASK) {
   case OBJ_SEARCH_OBJECT:
      {
         const struct ao2_reg_container *reg_right = obj_right;

         cmp = strcasecmp(reg_left->name, reg_right->name);
      }
      break;
   case OBJ_SEARCH_KEY:
      {
         const char *name = obj_right;

         cmp = strcasecmp(reg_left->name, name);
      }
      break;
   case OBJ_SEARCH_PARTIAL_KEY:
      {
         const struct ao2_reg_partial_key *partial_key = obj_right;

         cmp = strncasecmp(reg_left->name, partial_key->name, partial_key->len);
      }
      break;
   default:
      /* Sort can only work on something with a full or partial key. */
      ast_assert(0);
      cmp = 0;
      break;
   }
   return cmp;
}
#endif   /* defined(AO2_DEBUG) */

#if defined(AO2_DEBUG)
static void ao2_reg_destructor(void *v_doomed)
{
   struct ao2_reg_container *doomed = v_doomed;

   if (doomed->registered) {
      ao2_t_ref(doomed->registered, -1, "Releasing registered container.");
   }
}
#endif   /* defined(AO2_DEBUG) */

int ao2_container_register(const char *name, struct ao2_container *self, ao2_prnt_obj_fn *prnt_obj)
{
   int res = 0;
#if defined(AO2_DEBUG)
   struct ao2_reg_container *reg;

   reg = ao2_t_alloc_options(sizeof(*reg) + strlen(name), ao2_reg_destructor,
      AO2_ALLOC_OPT_LOCK_NOLOCK, "Container registration object.");
   if (!reg) {
      return -1;
   }

   /* Fill in registered entry */
   ao2_t_ref(self, +1, "Registering container.");
   reg->registered = self;
   reg->prnt_obj = prnt_obj;
   strcpy(reg->name, name);/* safe */

   if (!ao2_t_link(reg_containers, reg, "Save registration object.")) {
      res = -1;
   }

   ao2_t_ref(reg, -1, "Done registering container.");
#endif   /* defined(AO2_DEBUG) */
   return res;
}

void ao2_container_unregister(const char *name)
{
#if defined(AO2_DEBUG)
   ao2_t_find(reg_containers, name, OBJ_UNLINK | OBJ_NODATA | OBJ_SEARCH_KEY,
      "Unregister container");
#endif   /* defined(AO2_DEBUG) */
}

#if defined(AO2_DEBUG)
static int ao2_complete_reg_cb(void *obj, void *arg, int flags)
{
   struct ao2_reg_container *reg = obj;

   if (ast_cli_completion_add(ast_strdup(reg->name))) {
      return CMP_STOP;
   }

   return 0;
}
#endif   /* defined(AO2_DEBUG) */

#if defined(AO2_DEBUG)
static char *complete_container_names(struct ast_cli_args *a)
{
   struct ao2_reg_partial_key partial_key;

   if (a->pos != 3) {
      return NULL;
   }

   partial_key.len = strlen(a->word);
   partial_key.name = a->word;
   ao2_callback(reg_containers, partial_key.len ? OBJ_SEARCH_PARTIAL_KEY : 0,
      ao2_complete_reg_cb, &partial_key);

   return NULL;
}
#endif   /* defined(AO2_DEBUG) */

#if defined(AO2_DEBUG)
AST_THREADSTORAGE(ao2_out_buf);

/*!
 * \brief Print CLI output.
 * \since 12.0.0
 *
 * \param where User data pointer needed to determine where to put output.
 * \param fmt printf type format string.
 *
 * \return Nothing
 */
static void cli_output(void *where, const char *fmt, ...) __attribute__((format(printf, 2, 3)));
static void cli_output(void *where, const char *fmt, ...)
{
   int res;
   struct ast_str *buf;
   va_list ap;

   buf = ast_str_thread_get(&ao2_out_buf, 256);
   if (!buf) {
      return;
   }

   va_start(ap, fmt);
   res = ast_str_set_va(&buf, 0, fmt, ap);
   va_end(ap);

   if (res != AST_DYNSTR_BUILD_FAILED) {
      ast_cli(*(int *) where, "%s", ast_str_buffer(buf));
   }
}
#endif   /* defined(AO2_DEBUG) */

#if defined(AO2_DEBUG)
/*! \brief Show container contents - CLI command */
static char *handle_cli_astobj2_container_dump(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
   const char *name;
   struct ao2_reg_container *reg;

   switch (cmd) {
   case CLI_INIT:
      e->command = "astobj2 container dump";
      e->usage =
         "Usage: astobj2 container dump <name>\n"
         "  Show contents of the container <name>.\n";
      return NULL;
   case CLI_GENERATE:
      return complete_container_names(a);
   }

   if (a->argc != 4) {
      return CLI_SHOWUSAGE;
   }

   name = a->argv[3];
   reg = ao2_t_find(reg_containers, name, OBJ_SEARCH_KEY, "Find registered container");
   if (reg) {
      ao2_container_dump(reg->registered, 0, name, (void *) &a->fd, cli_output,
         reg->prnt_obj);
      ao2_t_ref(reg, -1, "Done with registered container object.");
   } else {
      ast_cli(a->fd, "Container '%s' not found.\n", name);
   }

   return CLI_SUCCESS;
}
#endif   /* defined(AO2_DEBUG) */

#if defined(AO2_DEBUG)
/*! \brief Show container statistics - CLI command */
static char *handle_cli_astobj2_container_stats(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
   const char *name;
   struct ao2_reg_container *reg;

   switch (cmd) {
   case CLI_INIT:
      e->command = "astobj2 container stats";
      e->usage =
         "Usage: astobj2 container stats <name>\n"
         "  Show statistics about the specified container <name>.\n";
      return NULL;
   case CLI_GENERATE:
      return complete_container_names(a);
   }

   if (a->argc != 4) {
      return CLI_SHOWUSAGE;
   }

   name = a->argv[3];
   reg = ao2_t_find(reg_containers, name, OBJ_SEARCH_KEY, "Find registered container");
   if (reg) {
      ao2_container_stats(reg->registered, 0, name, (void *) &a->fd, cli_output);
      ao2_t_ref(reg, -1, "Done with registered container object.");
   } else {
      ast_cli(a->fd, "Container '%s' not found.\n", name);
   }

   return CLI_SUCCESS;
}
#endif   /* defined(AO2_DEBUG) */

#if defined(AO2_DEBUG)
/*! \brief Show container check results - CLI command */
static char *handle_cli_astobj2_container_check(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
   const char *name;
   struct ao2_reg_container *reg;

   switch (cmd) {
   case CLI_INIT:
      e->command = "astobj2 container check";
      e->usage =
         "Usage: astobj2 container check <name>\n"
         "  Perform a container integrity check on <name>.\n";
      return NULL;
   case CLI_GENERATE:
      return complete_container_names(a);
   }

   if (a->argc != 4) {
      return CLI_SHOWUSAGE;
   }

   name = a->argv[3];
   reg = ao2_t_find(reg_containers, name, OBJ_SEARCH_KEY, "Find registered container");
   if (reg) {
      ast_cli(a->fd, "Container check of '%s': %s.\n", name,
         ao2_container_check(reg->registered, 0) ? "failed" : "OK");
      ao2_t_ref(reg, -1, "Done with registered container object.");
   } else {
      ast_cli(a->fd, "Container '%s' not found.\n", name);
   }

   return CLI_SUCCESS;
}
#endif   /* defined(AO2_DEBUG) */

#if defined(AO2_DEBUG)
static struct ast_cli_entry cli_astobj2[] = {
   AST_CLI_DEFINE(handle_cli_astobj2_container_dump, "Show container contents"),
   AST_CLI_DEFINE(handle_cli_astobj2_container_stats, "Show container statistics"),
   AST_CLI_DEFINE(handle_cli_astobj2_container_check, "Perform a container integrity check"),
};
#endif   /* defined(AO2_DEBUG) */

#if defined(AO2_DEBUG)
static void container_cleanup(void)
{
   ao2_t_ref(reg_containers, -1, "Releasing container registration container");
   reg_containers = NULL;

   ast_cli_unregister_multiple(cli_astobj2, ARRAY_LEN(cli_astobj2));
}
#endif   /* defined(AO2_DEBUG) */

int container_init(void)
{
#if defined(AO2_DEBUG)
   reg_containers = ao2_t_container_alloc_list(AO2_ALLOC_OPT_LOCK_RWLOCK,
      AO2_CONTAINER_ALLOC_OPT_DUPS_REPLACE, ao2_reg_sort_cb, NULL,
      "Container registration container.");
   if (!reg_containers) {
      return -1;
   }

   ast_cli_register_multiple(cli_astobj2, ARRAY_LEN(cli_astobj2));
   ast_register_cleanup(container_cleanup);
#endif   /* defined(AO2_DEBUG) */

   return 0;
}